Recent advances in communication, computing and storage technologies have led to new continuous media applications with high resource and stringent performance requirements. For example, some available media-on-demand systems are capable of providing media clips such as movies to clients on a real-time basis. Thus, a plurality of clients may request and retrieve one or more media contents as desired. Typically, the media contents, such as videos are stored on secondary storage devices on the server and delivered to the clients.
There has been some solutions suggested in literature to improve quality of service for media servers. For example, one solution to overcome memory bottlenecking problems provides an arrangement of a media server system that statistically replicates popular movies on multiple secondary storage devices based on the expected load, such that the total demand for the movie can be spread among the devices having a copy of the movie.
Another solution employs dynamic replication mechanisms, such that movies or portions of movies are copied, as a function of present demand, from heavily loaded storage devices to more lightly loaded storage devices.
Further approaches include "round-based" disk scheduling arrangement intended to handle real-time requirements of continuous media data as described in Designing File Systems for Digital Video and Audio in Proceedings of the Thirteenth ACM Symposium on Operating Systems Principles, pp. 81-94 (P. V. Rangan and H. M. Vin 1991); A Framework for the Storage and Retrieval of Continuous Media Data in Proceedings of the 1995 International Conference on Multimedia Computing and Systems, pp. 2-13 (B. Ozden, R. Rastogi, and A. Silberschatz 1995); The Storage and Retrieval of Continuous Media Data in Multimedia Database Systems: Issues and Research Directions, pp. 237-261 (B. Ozden, R. Rastogi, and A. Silberschatz 1996).
Another solution described in An Online Video Placement Policy based on Bandwidth to Space Ratio (BSR) in Proceedings of the 1995 ACM SIGMOD International Conference on Management of Data, (A. Dan and D. Sitaram 1995) presents a simulation based study of a load balancing arrangement for video servers. Similarly, DASD Dancing: A Disk Load Balancing Optimization Scheme for Video-On-Demand Computer Systems in Proceeding of the 1995 ACM SIGMETRICS Conference on Measurement & Modeling of Computer Systems (J. L. Wolf, P. S. Yu and H. Shachnai 1995) describes a system that employs dynamic load-balancing arrangement based on a heuristic graph-based algorithm employing combinatorial optimization techniques.
Although the above references and other available references describe systems and methods that can improve the performance of media servers and specifically the total throughput of such servers, there is a need for improving resource scheduling of such servers regardless of the throughput available by the server. Such resource scheduling is intended to improve the use of the total available throughput of a server system as explained hereinafter.